The PACE trial and behavioural treatments for M.E.

August 29, 2018

This statement sets out our position on the PACE trial and behavioural treatments for M.E.

In the past, Action for M.E.’s strategy was to support all forms of research into M.E. As part of this strategy, the charity was asked to be involved in a large-scale research project, the PACE trial, which compared standardised specialist medical care (SMC) alone, with SMC plus adaptive pacing therapy (APT), cognitive behavioural therapy (CBT), or graded exercise therapy (GET) for people with M.E./CFS.

Serious concerns about the PACE trial are well documented, with repeated questions raised about its methodology, and the reliability of its results. As reported in The Times newspaper last week, an open letter to The Lancet, signed by more than 100 scientists, clinicians, parliamentarians and patient organisations, including Action for M.E., has been sent three times, asking the journal to reanalyse the trial’s findings.

Concerns about the trial include:

broad criteria for entry into the trial meant that patients who did not experience post-exertional malaise were included, so it cannot be assumed that the results of the trial apply to patients who have this symptom

the PACE trial did not use objective measures to assess the effectiveness of CBT and GET, but instead relied on subjective measures, ie. reporting by patients, which can be unreliable

the models of GET and CBT used in the PACE trial assume that M.E. is perpetuated by deconditioning (lack of fitness); however, significant studies disagree that deconditioning is the cause of M.E. and/or CFS, and is in fact a consequence of the condition.

changes to the recovery criteria part-way through the trial meant that “it was possible to score below the level required for trial entry, yet still be counted as ‘recovered’” (Wilshire et al, 2016)

the original analysis of the study data “did not consistently follow the procedures set out in the published protocol, and it is unclear whether the conclusions are fully justified by the evidence” (Wilshire et al, 2018).

Two of the charity’s previous Chief Executives (prior to 2011) served as independent members of the Trial Steering Committee, and sat on the Trial Management Group. Action for M.E. did not receive any payment for this, and made no contribution to the funding of the trial.

Sonya Chowdhury, our Chief Executive since September 2012, says: “By having a role on the Steering Committee and Management Group, there was a de facto endorsement of the use of £5m of research funding to focus on behavioural treatments. Neither I nor the current Board of Trustees would agree to do this now, as reflected by our current research strategy, the focus of which is collaborative biomedical research.

“I am sorry that the charity did not advocate for this considerable level of funding to be invested in biomedical research instead. It was never our intention to contribute to any stigma or misunderstanding about the illness and I sincerely apologise to those who feel that, in not speaking out sooner and more strongly, we have caused harm.

“Our position on recommending treatment and management approaches for M.E. is set out below and, over the coming months, we will review all our printed and online information to reflect this. This is no small task, but one that the team will prioritise and complete as quickly and comprehensively as we can.

“We will learn from our past mistakes. We will continue to provide practical support to our Supporting Members and others with M.E., to challenge the stigma and neglect they experience, and work with professionals and policy-makers to transform the lives of children, young people and adults with M.E. in the future.”

A summary of our position

Action for M.E. does not support any treatment approach:

based on the deconditioning hypothesis

in which patients’ legitimate concerns about the consequences of exercise are dismissed or ignored.

We fully support treatment approaches which:

aim to reduce and stabilise symptoms before any appropriate increase in activity levels is attempted

put the person with M.E./CFS in charge of the aims and goals of the overall management plan.

We would like to see:

clarity from specialist NHS M.E./CFS services about the approaches they offer, and the theoretical basis behind them, to help patients make informed decisions about the treatments they
are being offered

health services and commissioners working directly with people affected by M.E. to develop patient-led services

good-quality, independent evaluation of the programmes being offered by specialist NHS M.E./CFS services.

Our position, with a longer explanation

The aim of the APT approach tested in the PACE trial was defined in the therapist’s manual for the trial as:“To stabilise the symptoms and activity with the anticipated benefit of: (a) maximizing what can be achieved within a limited amount of energy; (b) preventing exacerbation of symptoms and disability; (c) enabling participants to plan activities; (d) providing the best environment for the body to naturally recover; (e) allowing gradual increases in activity as the participant feels able.”

The aim of the GET approach tested in the PACE trial was defined in the therapist’s manual for the trial was to: “help the participant to gradually engage and participate in physical activity and aerobic exercise […] “GET differs from CBT by not directly targeting cognitive factors and from APT by encouraging the participant to extend their physical functioning beyond their current ability. […] GET assumes that CFS/ME is perpetuated by deconditioning (lack of fitness), reduced physical strength and altered perception of effort consequent upon reduced physical activity.”

However, M.E./CFS is not caused by deconditioning, nor are its symptoms explained by inactivity. It is a complex, multi-system disease involving neurological, immunological, autonomic, and energy metabolism impairments. The debility in M.E./CFS is much greater than is seen with deconditioning. (Van Ness et al, Workwell Foundation, May 2018)

For this reason, Action for M.E. does not support any therapeutic approach that assumes M.E./CFS is based on deconditioning.

CBT was defined in the therapist’s manual for the PACE trial as “complex incremental pacing” which involves “elements of simple pacing to stabilise activity, graded increases in activity […] and also directly addresses participant’s beliefs and fears about their symptoms and functioning.”

This type of CBT is based on “a theoretical model, which supposes that unhelpful interpretations of symptoms, fearful beliefs about engaging in activity, and excessive focus on symptoms are central in driving disability and symptom severity. These cognitive responses are associated with unhelpful behavioural patterns, including avoidance of activity or all-or-nothing behaviour – a pattern of excessive resting alternating with pushing too hard or being overactive when well.” (Chalder et al, Lancet Psychiatry, 2015)

The paper this quote is taken from cites “I am afraid that I will make my symptoms worse if I exercise” as an example of a “fear avoidance beliefs.”

However, studies have demonstrated that even mild exercise can provoke symptoms. This low tolerance for physical activity is typified by an abnormally early transition to anaerobic metabolism. (Van Ness et al, Workwell Foundation, May 2018)

For this reason, Action for M.E. does not support any therapeutic approach in which patients’ legitimate concerns about the consequences of exercise are dismissed or ignored.

What about pacing?

The NICE guideline for M.E./CFS acknowledges that APT is just one of the definitions people might mean when they use the word pacing. It says: “In this guideline, pacing is defined as energy management, with the aim of maximising cognitive and physical activity, while avoiding setbacks/relapses due to overexertion. The keys to pacing are knowing when to stop and rest by listening to and understanding one’s own body, taking a flexible approach and staying within one’s limits; different people use different techniques to do this.

“However, in practice, the term pacing is used differently by different groups of people. One understanding of its meaning is as adaptive pacing therapy, which is facilitated by healthcare professionals, in which people with CFS/ME use an energy management strategy to monitor and plan their activity, with the aim of balancing rest and activity to avoid exacerbations of fatigue and other symptoms.

“Another understanding is that pacing is a self-management strategy, without specific intervention from a healthcare professional. People with CFS/ME generally support this approach.”

In its guidance on therapy and symptom management, the British Association for CFS/M.E. does not refer to APT and/or pacing. Instead, it offers “pragmatic recommendations from experienced clinicians to guide practice when seeing adults with CFS/M.E., where specialist CFS/M.E. CBT and GET therapists are not available/appropriate […] Evidence-based therapies emphasize a therapeutic relationship that enables a graded increase in activity and a process to explore barriers to this increase.”

According to BACME, specialist NHS M.E./CFS services should advocate collaborative work, patient-led goals and support to stabilise physiological patterns of rest, sleep, movement and diet. At the same time, psychological/emotional support should be offered, aimed at supporting patients to come to terms with being diagnosed and/or living with the condition, and to understand the factors and behaviours (eg. doing too much) that jeopardises that stabilisation.

We fully support this approach, and would add that:

“this is best achieved through pacing that utilizes energy conservation techniques mindful of heart rate limits. Only then can careful training of the anaerobic energy system, (ie, improving the body’s tolerance for and ability to clear lactate while increasing ATP in resting muscle) be initiated.” (Van Ness et al, Workwell Foundation, May 2018)

“healthcare professionals should recognise that the person with CFS/ME is in charge of the aims and goals of the overall management plan. The pace of progression throughout the course of any intervention should be mutually agreed.” (NICE guideline for M.E./CFS, 2007)

We hear from many patients who say that they have received exactly this sort of support from the clinician working with them. However, we also hear from patients who feel that they are pushed to do too much, or whose therapists or other health professional do not take their views and experiences into account.

We would like to see:

clarity from specialist NHS M.E./CFS services about the approaches they offer, and the theoretical basis behind them

health services and commissioners working directly with people affected by M.E. to develop patient-led services

good-quality, independent evaluation of the programmes being offered by specialist NHS M.E./CFS services.

As indicated above, we will review all our printed and online information to reflect our position, as quickly and comprehensively as we can, but please be aware that this may take some time.